For example, a sputtering apparatus that forms a metal film on a semiconductor wafer includes a collimator for aligning directions of metal particles to be deposited. The collimator has walls with a large number of through holes to allow to pass therethrough substantially vertically flying particles and to block obliquely flying particles with respect to an object to be processed such as a semiconductor wafer.
The directions of the particles passing through the collimator can be inclined within a predetermined range relative to a desired direction. The collimator may block usable, obliquely flying particles in addition to unnecessary particles.